The entrance channel dependence of the isospin effects of nuclear stopping in intermediate energy heavy-ion collisions has been studied by using an isospin-dependent quantum molecular dynamics with three different kinds of symmetry potentials. It is shown that nuclear stopping is sensitive to the beam energy, the impact parameter and the mass of the colliding system, especially very sensitive to the isospin dependence of the in-medium nucleonnucleon cross section, but insensitive to the symmetry potential and the neutron-to-proton ratio of the colliding system. From this investigation, it is proposed that nuclear stopping can be used as a new probe to extract the information on the isospin dependence of the in-medium nucleon-nucleon cross section in intermediate energy heavy-ion collisions.